1. Field of the Invention
The present invention relates to a lamp mounting structure to a bumper of an automobile, in particular to a structure for mounting a lamp such as side marker or the like to a side section of a bumper which is attached to a body of an automobile in the vicinity of a wheel housing thereof.
2. Description of the Prior Art
One of the conventional lamp mounting structures for a bumper of an automobile is illustrated in FIGS. 1 to 3.
In FIG. 1, the reference numeral 1 denotes a bumper of an automobile. The bumper 1 comprises an armature (not shown in the drawings) which acts as a reinforcing member of the bumper 1 and a bumper facer 2, which is a facing member of the bumper 1, attached onto the armature. The left and right side sections 1a of the bumper 1 are bent inwardly, respectively. The bumper 1 having the above configuration is mounted to a body 4 of the automobile in such a manner that each of the left and right side sections 1a are directed to left and right wheel housings 3 of the automobile, respectively. Accordingly, when the bumper 1 is mounted to the body 4, the upper side 2a of the bumper facer 2 at each of the left and right side sections 1a of the bumper 1 is joined to a fender panel 5 as shown in FIG. 2 and the back end portion 2b thereof faces the wheel housing 3, respectively.
In each of the back end portions 2b of the facer 2, there is formed an elongated concave portion 7. The concave portion 7 has a base part 7a at the bottom thereof. In the base part 7a, there are formed two mounting holes 8 with a certain space therebetween and an opening 9 between the mounting holes 8. In the concave portion 7 having the above structure, a lamp 10 such as a side marker having a configuration similar to that of the concave portion 7 is installed.
The lamp 10 includes a base plate portion 11 and a bulb 12 supported on the base plate portion 11. A wiring harness 13 which extends into the inside of the body 4 through the opening 9 is connected to the bulb 12 of the lamp 10. On the rear surface 11a of the base plate portion 11 of the lamp 10, there are integrally formed two bosses 14, which serve as mounting seats of the lamp 10. The bosses 14 are arranged on the rear surface 11a of the base plate portion 11 so as to correspond to the positions of the mounting holes 8 formed in the base part 7a of the concave portion 7, and each of the bosses 14 has an axial screw hole 14a. In addition, on the rear surface 11a of the base plate portion 11, a rectangular tubular portion 15 which covers the opening 9 is protrudingly formed between the bosses 14 so as to surround the wiring harness 13. The protruding length of the tubular portion 15 is the same as that of each boss 14. Accordingly, the lamp 10 is mounted to the concave portion 7 of the bumper facer 2 by inserting the lamp 10 into the concave portion 7 from the rear side thereof, aligning the screw holes 14a of the bosses 14 to the mounting holes 8 of the base part 7a, and then screwing screws 16 into the screw holes 14a of the bosses 14 through the mounting holes 8 from the rear of the base part 7a.
In the meantime, around the wheel housing 3, a portion of a quantity of muddy water W which is splashed out from the inside of the wheel housing 3 is liable to enter the inside of the fender panel 5 through very small gaps in the wheel housing 3. Therefore, according to the conventional lamp mounting structure as described above, there is a case that the muddy water W entered into the fender panel 5 is transmitted to the inner surface of the bumper facer 2 and flows down as far the rear portion of the concave portion 7 of the bumper facer 2, as illustrated in FIG. 2. The muddy water W then enters the concave portion 7 from the opening 9 formed in the base part 7a, because the end of the tubular portion 15, though it covers the opening 9, simply contacts the base part 7a at the periphery of the opening 9. Namely, the conventional structure is not enough to prevent the muddy water from entering the concave portion 7. The muddy water entered into the concave portion 7 then flows out to reach the outer surface of the bumper facer 2, and therefore soils the outer surface of the bumper facer 2.
In view of this, as shown in FIG. 2, it is proposed that a rubber gasket 17 is interposed between the lower surface of the tubular portion 15 and the inner surface of the concave portion 7. However, the use of this rubber gasket 17 increases the number of parts used, so that this is a disadvantage in assembly process and manufacturing cost.
In addition, in the conventional structure the positioning accuracy of the lamp 10 with respect to the concave portion 7 is determined by the relationship between the mounting holes 8 and the screws 16 which are screwed into the screw holes 14a of the bosses 14, so that the diameter of the mounting hole 13 cannot be much greater than that of the screw 16. Specifically, if the diameter of the mounting hole 8 is fairly large with respect to the diameter of the screw 16, the space between the lamp 10 and the concave portion 7 is liable to be not uniform (in particular, the vertical spaces S in FIG. 3, which is very conspicuous from the outside). This has an adverse effect on the outer appearance ends of the automobile and detracts from the image of quality. In this case, if the positioning accuracy of the lamp 10 in the concave portion 7 is improved by merely reducing the diameter of each mounting hole 8, it becomes extremely difficult to line up the mounting hole 9 with the screw holes 14a of the bosses 14 and then insert the screws 16 to the mounting holes 8. This is another disadvantage from the aspect of mounting operability.